Method of treating sounding boards of stringed instruments



Oct. 5, 1926.

P. A. R. FRANK METHOD OF TREATING SOUNDING BOARDS OF STRINGED INSTRUMENTS Filed August 19, 1922 lnvenfiofi Pal/Z A. R. Frank Attorney Patented Oct. 5, 1926.

METHOD OF TREATING SOUND I 3&4?"

Application filed August 19, 1922, ,fcriaz 2T0. EESJJSO,

Hitherto various methods have been suggested for improving the tone of string instruments, in particular violins. In accordance with these known methods the instrument either is treated externally by means of special substances or is mechanically modified, internally, or the bottom and top boards are covered or coated with special. materials.

The improvement of the tone of the instrument results from the production of line elastic membranes over the pores of the )(l, said menibrai'ies bei oted to incmise or intensify the r the wood. In the prior art said elastic meinluranes were produced lj means of solr' which were painted on the wood, in the old. methods failed. since the t to the wood lost their elast ca longer or shorter space of time and the uscful effect thereof then was over. in most cases a contrary effect would then be pro duced. The hardened substances produced disagreeable wrong notes. In violins the sounding waves are mainly distributed by the resonance or sounding-board, the frame and the lower board or bottom having a minor effect only.

The present invention relates to a method which, as regards its effect, is independent of solidified solutions. The object of the new method is to give the resonance or sounding-board and, if desired, also the lower board or bottom of the instrument, such a tension as to cause all of the wooden parts to vibrate uniformly. At the same time, however, a lowering effect will be produced whereby the resonance vibrations are shortened which is necessary in order to ensure a wider range of the sound.

With this object in view the inner surface of the sounding board is coated with a line fabric, preferably made of silk, in such a manner that the said fabric or tissue will be in intimate contact all over with the face of the wood. To fix and firmly connect the said fabric to the wood a suitable aggluti nant is employed which may be of animal or vegetal or even inorganic nature.

The provision of a fixed layer of fabric of this kind ensures that all parts of the wood are brought in connection with each other in order to cause the whole board to vibrate uniformly. All harshness and wrong or discordant notes disappear. The fabric in coaction with the agglutinant overlies the UNITED STATES smear oesics.

' any August 20, 1921.

form microscopically fine the same time, however, es of the fabric a :uiltitude of fine air holes or vesited to act in th *ir turn as tiny resocles thickness of 1 ad on the nafine fabagglutinant are notes will be thicker or or who used utinant, will vibrations all. and any cas s the uniform- "ene s of all the sounds or notes no. Hence by properly select ',1ilar sort of agglutinant and a ;(.iilCll.=il' l? \t of fabric any desire with regard to the timbre of the instrument may be complied with.

in some cases it may be found necessary to provide special improving means for the G and the Dstring. In accordance with the resent invention the note or sound from the G- and the D-string' will be essentially improved or intensified if the outer of the inner side or face of the resonance board is pro ided with a double layer of fabric or if the layer or fabric is fixed andv connected to the board by means of a hard agglutinant, or if both expedicnts are adopted.

The high tones will. be of a particularly soft and sweet timbre in case the median section of the board is provided with a layer of very fine sill: ;'al3ric attached to the board by means of soft elastic agelutinant. If it is desired to protect he apggrlutinant from the action of moist air it will be advisable to give the properly attached protective fabric coatand to use for the latter purpose a solution of resins (varnish) or drying and resinifying oils.

The accompanying drawing shows a crosssectional view of a violin, the inner or lower surface of the sounding board a of which is covered with fine silk fabric 1) that is firmly secured thereto by a suitable agglutinant.

From the foregoing description it will be seen that simple and eilicient means are herein provided for accomplishing the object of 

